Various methods and techniques for enhancing the recovery of oil and gas from a producing well have been advanced over the years. One such approach is to employ a plunger lift which, as a method of artificial lift, utilizes the well's own energy to produce the reservoir fluids which the well normally cannot expel under natural flow and is typically employed in de-watering gas wells, enhancing recovery from high gas/oil ratio wells and for cutting paraffin. In a typical plunger lift installation, the plunger lift is installed in the production string and becomes an interface between the fluid and gases as it travels to the surface to expel fluid. The plunger movement is controlled by a cyclical operation which creates a differential across the plunger and normally is accomplished by opening and closing a valve under the control of a time cycle controller or other automatic pressure-actuated controller. Of course, the type of well, method of well completion and production facilities will determine the specific type of wellhead controls and equipment required for optimum production.
In order to minimize the possibility of jamming the plunger lift as it travels through the tubing string, it has been proposed in the past to provide a rotor or spinning element on a portion of the lift which rotates independently of the rest of the lift for the purpose of creating turbulence and increase the sealing effect between the lift and the walls of the tubing string so as to reduce the escape of gas around the lift. Representative of this approach is U.S. Pat. No. 4,007,784 to W. L. Watson et al. A similar approach is taken in U.S. Pat. No. 4,410,300 to H. W. Yerian in which slots at one end of the lift serve to deflect escaping gas streams and promote turbulence to improve the gas sealing capability as well as to minimize the risk of jamming. Typical of other approaches to the construction of plunger lift units are disclosed in U.S. Pat. Nos. 1,992,396 to N. H. Ricker; 2,417,349 to S. G. Colbaugh; 3,179,022 to P. S. Bloudoff; and 4,030,858 to O. C. Coles, Jr. However, to the best of my knowledge, all of these devices as well as others in commercial use have suffered definite limitations particularly in connection with their use in low pressure wells having a pressure as low as 60 psi. A principal reason is that spinning or rotational forces are not created along the substantial length of the lift and does not provide an effective means for the controlled leakage of fluid past or through the lift as it is caused to rise by virtue of the differential pressure in the tubing string.